1. Field of the Invention
The present invention relates to a method for recording information on an information record medium having a plurality of records thereon and an apparatus therefor.
2. Related Background Art
Various media such as disk, card and tape types have been used as information record media to optically record information and read the recorded information. Of those, a card-like optical information record medium (optical card) is compact, light and easy to carry, and a large demand thereof is expected as a convenient large capacity information record medium.
FIG. 1 shows a schematic plan view of an optical card, and FIG. 2 shows a partial enlarged view thereof.
In FIG. 1, numeral 1 denotes an optical card, numeral 2 denotes an information track, and numeral 3 denotes a home position. The optical card 1 is modulated with record information and a light beam focused into a fine spot is scanned on the optical card so that information is recorded as a record pit line (information track) which is optically detectable. In order to correctly record and reproduce information without trouble such as crossing of the information track 2, it is necessary to control the irradiation position of the light beam perpendicularly to a scan direction (autotracking AT). In order to irradiate the fine spot stably in spite of warp of the optical card or mechanical tolerance, it is necessary to control the irradiation position of the light beam normally to the optical card (auto-focusing AF). As shown in FIG. 2, tracking tracks 5 (5.sub.1, 5.sub.2, . . . ) for AT are provided between the information tracks 2 (2.sub.1, 2.sub.2, . . . ) of the optical card 1.
Recording and reproducing methods of the optical card are now explained.
In FIG. 1, the light beam is initially at the home position 3. Then, the light beam move in a direction D, finds an information track 2N to or from which information is to be recorded or reproduced, and scans the information track 2N in a direction F to record or reproduce information.
In order to determine whether the track is a target track or not, track number areas 6 (preformat) which prerecord track numbers are formed on extended lines of the tracking tracks 5 (5.sub.1, 5.sub.2, . . . ), the recorded track number is read and the content thereof is checked to determine whether it is the target track or not. Alternatively, data plus a track number is recorded on the information track 2 (2.sub.1, 2.sub.2, . . . ), the information track is reproduced and the track number is extracted and compared with the target track number. For example, the former method is described in U.S. patent application Ser. No. 846,888 filed on Apr. 1, 1986, now abandoned, and assigned to the assignee of the present invention.
However, in the former method, an application is restricted depending on the preformat. In the latter method, since no information is written on a non-recorded track, it is impossible to determine whether the track is the target information track or not, and it may be overwritten if it follows a recorded information track by error.
Where the optical information record medium is a non-erasable after-record type record medium, the recorded data is immediately reproduced, it is verified to determine whether it is identical to the record data, and if it is not identical, it is again recorded in the next information track. However, it may be possible that an error occurs when the information is reproduced from the information record medium. When the error occurs, it is impossible to determine whether it is due to dust or break in the reproduce operation or it has existed since the record operation. So-called retry to repeat the reproduction when the error occurs is usually carried out a plurality of times in the reproduce operation, and if the error still occurs, the information is reproduced from the next information track. However, if there are many error tracks in the record operation, the number of times of extra retries increases and a reproduce time is extended.